Sampling system and analysis cell for stripping voltammetry

Abstract

A combination sampling/electrochemical analysis cell comprises an enclosure having a hollow therein, at least one inlet leading to the hollow, a vent leading from the hollow, at least one testing electrode, at least one counter electrode, and at least one reference electrode, all disposed at least in part in the hollow. A testing reagent is also contained in the hollow.

I claim: 
     
       1. A disposable combination capillary sampling/electrochemical analysis cell comprising an enclosure having a hollow therein, at least one capillary inlet leading to said hollow wherein said inlet permits uptake of the material being sampled, a vent leading from said hollow, at least one testing electrode, at least one counter electrode, and at least one reference electrode, all disposed in part in said hollow, said hollow further including a testing reagent. 
     
     
       2. A cell according to claim 1, wherein said testing reagent is deposited at least in part in contact with said testing electrode. 
     
     
       3. A cell according to claim 1, wherein said testing reagent is dried in place on said testing electrode. 
     
     
       4. A cell according to claim 3, wherein said testing reagent comprises a mixture of an acid and one or more salts. 
     
     
       5. A cell according to claim 4, wherein said salt is selected from the group consisting of an alkali metal, salt, a rare earth divalent cation, a rare earth trivalent cation, and mixtures thereof. 
     
     
       6. A cell according to claim 5, wherein said alkali salt is selected from the group consisting of LaCl 3 , AlCl 3 , CrCl 3 , CaCl 2 , HgCl 2 , and mixtures thereof. 
     
     
       7. A cell according to claim 4, wherein said acid comprises an organic acid. 
     
     
       8. A cell according to claim 7, wherein said organic acid comprises monochloro acetic acid. 
     
     
       9. A cell according to claim 1, wherein said reagent also comprises a surfactant. 
     
     
       10. A cell according to claim 1, wherein said at least one testing electrode comprises a plurality of spaced carbon or graphite fibers electrically connected to a common bus. 
     
     
       11. A cell according to claim 10, wherein said carbon or graphite fibers are disposed generally transverse to the inlet. 
     
     
       12. A cell according to claim 1, and further comprising an expansion area in said inlet. 
     
     
       13. A cell according to claim 1, having a working volume of less than about 100 μl. 
     
     
       14. A capillary sampling cell incorporating at least one testing electrode, at least one counterelectrode, at least one reference electrode, a testing reagent in the cell, and a capillary inlet which permits uptake of the material being sampled. 
     
     
       15. A cell according to claim 14, wherein said testing reagent is deposited at least in part in contact with said testing electrode. 
     
     
       16. A cell according to claim 14, wherein said testing reagent is dried in place on said testing electrode. 
     
     
       17. A cell according to claim 14, wherein said testing reagent comprises a mixture of an acid and one or more salts. 
     
     
       18. A cell according to claim 17, wherein said salt is selected from the group consisting of an alkali metal, salt, a rare earth divalent cation, a rare earth trivalent cation, and mixtures thereof. 
     
     
       19. A cell according to claim 18, wherein said alkali salt is selected from the group consisting of LaCl 3 , AlCl 3 , CrCl 3 , CaCl 2 , HgCl 2 , and mixtures thereof. 
     
     
       20. A cell according to claim 17, wherein said acid comprises an organic acid. 
     
     
       21. A cell according to claim 20, wherein said organic acid comprises monochloro acetic acid. 
     
     
       22. A cell according to claim 14, wherein said reagent also comprises a surfactant. 
     
     
       23. A cell according to claim 14, wherein said at least one testing electrode comprises a plurality of spaced carbon or graphite fibers electrically connected to a common bus. 
     
     
       24. A cell according to claim 23, wherein said carbon or graphite fibers are disposed generally transverse to the inlet. 
     
     
       25. A cell according to claim 14, having a working volume of less than about 100 μl. 
     
     
       26. A cell according to claim 1, wherein said cell includes a reagent for treating a human blood sample preparatory to electrically detecting and measuring lead content of said sample, wherein said reagent comprises a mixture of an organic acid and a salt selected from the group consisting of LaCl 3 , AlCl 3 , CrCl 3 , CaCl 2 , HgCl 2  and mixtures thereof. 
     
     
       27. A reagent according to claim 26, wherein said organic acid comprises monochloro acetic acid. 
     
     
       28. A cell according to claim 1, wherein said inlet terminates in a sharpened bevel. 
     
     
       29. A cell according to claim 14, wherein said cell includes an inlet tube sharpened at its distal end.